An actor who takes the place of another actor in scenes requiring special skills or preparations:
A backup copy of data, a file, etc.
Substitute is defined as a person or thing acting in place of something else.
An alternate is defined as a person who takes the place of another.
(Statistics) The act of returning each item that has been selected in a subset from a group before making another selection.
A person or thing ready to serve or be put into service on an emergency basis or as a substitute
Find another word for understudy. In this page you can discover 12 synonyms, antonyms, idiomatic expressions, and related words for understudy, like: double, stand-in, backup, substitute, understudy-for, play-the-lead, leading lady, love-interest, accompanist, alternate and replacement.